Having decided earlier this year that this will be his final season, the Colorado Rockies decided to go public.

“I didn’t want to say I was going to return and then come back in,” Helton said before Sunday’s game against Arizona. “I talked to my wife and thought about my body and mentally how I felt going out there for every game. I’m 40. It’s time to go. It’s a young man’s game.”

Helton has spent his entire 17-year major league career with the Rockies and set franchise records in nearly every offensive category. He announced his decision after Saturday night’s 9-2 loss, when he hit his 586th double.

His final game at Coors Field is slated for Sept. 25 against Boston, which swept the Rockies in the 2007 World Series. The final game of his career figures to be Sept. 29 at the Los Angeles Dodgers.

Helton joins New York Yankees closer Mariano Rivera among players retiring this year. Rivera announced his decision during spring training.

“I wanted to go into the last homestand knowing it was the last,” Helton said. “It was brought up to me last week that I couldn’t look at it from my perspective. I had to look at it from the fans’ standpoint. I couldn’t be selfish about it.”

Helton began Sunday as a career .317 hitter with 367 homers, 1,397 RBIs, 1,394 runs, a .415 on-base percentage and a .539 slugging percentage. He was an All-Star from 2000-04 and is the Rockies’ leader in games, hits, doubles, home runs, RBIs, runs and walks. He also won three Gold Gloves at first base.

Helton won the NL batting title with a .372 average in 2000, when he led the league with 59 doubles and 147 RBIs and also hit 42 home runs.

In 2007, he hit .320 with 17 homers and 91 RBIs. Colorado won 14 of its final 15 regular-season games and seven straight playoff games before Boston’s sweep.

“Obviously, yeah, I wish we did win a World Series,” Helton said. “But when I look at it, I think I was very blessed, fortunate to be in the World Series. I look at the lot of things we did accomplish and not the one we didn’t.”